Need Help!!! Car is stuttering and Misfiring
 

Okay i have just installed new heads, cam, headers, ls6 ported oil pump, ls7 lifters, double roller timing chain, new TR55 spark plugs, and pacesetter headers, catted y-pipe.

The car starts up fine and seems to rev up good in neutral. When i start driving and putting the car under load it starts misfiring really bad and popping and has no power. The car is fully warmed up and is doing this. When i push the gas pedal down the car is misfiring and not wanting to accelerate.

If you put your spark plug in before putting in the new headers more than likely you put a crack or fineline in one of the plugs causing your symptoms.But since youve done so much other stuff to the vehicle im not sure

Ok, that's a good suggestion but I did install the headers before the spark plugs.

Could it possibly be a bad coil pack or plug wire?

Parts don't go bad during an install. Check to make sure all the plug wires are on securely, check your grounds - especially at the back of the heads, I assume you double checked the line up of the crank and cam gears, check your injector harnesses, check to make sure your 02 sensors are securely plugged and the sires aren't pinched or shorted.

Can you get the codes read for which cylinders are misfiring?

Would 02 sensors make the car run like this? I would assume it would be more towards ignition related. As far as the rest I have checked everything to make sure it was on correctly.

your o2 sensors have a huge impact on the way the car runs, as they provide feedback to the pcm on how to run the engine.

thanks everybody. i'll check 02 sensors. is there a way to tell if they are bad or not?

After putting new plug wires in the car had a hard time starting and I could smell fuel. Could it be that the car is running too rich and too much fuel is firing into the cylinders causing this misfire issue?

am i missing something obvious? i dont see a tune in yours mods list? this is the first thing to do after the install and the most important. if your not tuned it will most likely cause all those things. a 233/239 cam is pretty good size cam....

get a tune...

Yes i know. I'm getting it tuned tomorrow at LMR in Houston. I was just thinking that it seems you should at least be able to drive the car a little without it misfiring after installing heads/cam/headers. I will update once the tune is done. thanks